Varying Gap-Immersion Method for Measuring Dielectric Constant and Loss Tangent Angle

A method is described for measuring the dielectric constant and the loss tangent angle of sheet specimens at frequencies above 1 MHz without requiring the measurements of thickness. Through the combination of the gap variation method [1]-[5] and the immersion method [6], [9], the main source of error in the gapvariation method, i.e., the thickness measurement of the specimen, is avoided. Also avoided are the possible sources of error encountered in high-frequency measurements using the immersion method such as the series resistances of the electrodes, of the capacitors used in the measuring circuit, and of the lead wire connecting the electrode and the circuit. This method is easy to use and takes little time as compared with the conventional methods. The accuracy is expected to approach that of the low-frequency immersion method.